Some hydraulic excavators having hydraulic drive motors attached to the roller frames for driving the tracks are provided with a guard assembly to substantially enclose the drive motors. The present guard assemblies are attached solely to the car body. However, many of the hydraulic excavators are provided with a means to move the roller frames and tracks outwardly relative to the longitudinal axis of the vehicle to provide a wider track gauge. Moving the roller frames outwardly also moves the drive motors outwardly from the guard assembly thereby exposing at least a portion of each drive motor to potential damage by their impact with rocks, stumps or the like.